Gas distribution plate with high aspect ratio holes and a high hole density

ABSTRACT

A gas distribution plate for a showerhead assembly of a processing chamber may include at least a first plate and second plate. The first plate may include a first plurality holes each having a diameter of at least about 100 um. The second plate may include a second plurality of holes each having a diameter of at least about 100 um. Further, each of the first plurality of holes is aligned with a respective one of the second plurality of holes forming a plurality of interconnected holes. Each of the interconnected holes is isolated from each other interconnected holes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/802,293 filed Feb. 26, 2020, which claims priority to U.S.Provisional Patent Application Ser. No. 62/824,369 filed Mar. 27, 2019.Both the Ser. No. 16/802,293 and the 62/824,369 applications areincorporated herein by reference in their entireties.

BACKGROUND

Embodiments of the present disclosure generally relate to a showerheadfor processing chambers, and, more particularly, to a showerhead havinga high aspect ratio of holes and a high hole density for processingchambers.

Description of the Related Art

In many conventional showerhead designs, the showerhead includes a gasdistribution plate having a plurality of holes through which aprocessing gas may flow. However, the number of holes and the aspectratio of those holes may be limited. Hence, the uniformity of the flowof the processing gas through the showerhead is limited. A major factorin limiting the number of holes within a gas distribution plate is theprocess in which the holes are generated. For example, mechanicaldrilling of holes may place high levels of stress on the gasdistribution plate potentially damaging the gas distribution plateand/or may create burrs within the gas distribution plate. Further,mechanical drilling is time prohibitive and may be process limited. Forexample, in many instances, mechanical drilling utilizes a spindlecoolant fed drills, which are available in the smallest diameter size ofabout 500 um, limiting the smallest possible hole that may be drilled.Other subtractive drilling methods include ultrasonic drilling or microelectrical discharge machining (EDM), which are both time prohibitive. Afurther example of subtractive drilling includes laser drilling which istypically limited to about a 10:1 aspect ratio and which is also timeprohibitive. Accordingly, the conventional methods of generating holeslimit the size of the holes and the aspect ratio of the holes, whileincreasing the manufacturing cost of the gas distribution plate.Further, the conventional methods of holes generation limit the holedensity, which limits the uniformity of a process gas flowing throughthe gas distribution plate.

Therefore, in order to improve the uniformity of gas distribution, thereis a need for improved fabrication methods to create a large number ofsmall diameter holes in a gas distribution plate in a cost-effectiveway.

SUMMARY

In one embodiment, a gas distribution plate for a showerhead assemblyincludes a first plate and second plate. The first plate may comprise afirst plurality holes each having a diameter of at least about 100 um.The second plate may comprise a second plurality of holes each having adiameter of at least about 100 um. Further, each of the first pluralityof holes is aligned with a respective one of the second plurality ofholes forming a plurality of interconnected holes. Each of the pluralityof interconnected holes is isolated from each other of the plurality ofinterconnected holes.

In one embodiment, a method for forming a showerhead comprisesgenerating a first plurality of holes in a first plate and generating asecond plurality of holes in a second plate. Each of the first pluralityof holes has a diameter of at least about 100 um and each of the secondplurality of holes has a diameter of about 100 um. The method furthercomprises aligning each of the first plurality of holes with arespective one of the second plurality of holes to generate a pluralityof interconnected holes, and bonding the first plate to the secondplate. Each of the plurality of interconnected holes is isolated fromeach other of the plurality of interconnected holes.

In one embodiment, a processing chamber comprises a showerhead assembly,a substrate support configured to support a substrate and a gas supplyfluidly coupled with the showerhead assembly and configured to provide aprocess gas to the showerhead assembly. The showerhead assemblycomprises a gas distribution plate including a first plate and secondplate. The first plate comprises a first plurality holes each having adiameter of at least about 100 um. The second plate comprises a secondplurality of holes each having a diameter of at least about 100 um.Further, each of the first plurality of holes is aligned with arespective one of the second plurality of holes forming a plurality ofinterconnected holes, and each of the plurality of interconnected holesis isolated from each other of the plurality of interconnected holes.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofscope, as the disclosure may admit to other equally effectiveembodiments.

FIGS. 1 and 2A are schematic cross-sectional view of a gas distributionplate, according to one or more embodiments.

FIG. 2B is a schematic side view of a portion of a gas distributionplate, according to one or more embodiments.

FIG. 3 is a schematic cross-sectional view of gas distribution plate,according to one or more embodiments.

FIGS. 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H, and 41 are schematiccross-sectional view of a gas distribution plate, according to one ormore embodiments.

FIG. 5 illustrates a flow chart of a method for forming a gasdistribution plate, according to one or more embodiments.

FIG. 6 is a schematic side view of a process chamber, according to oneor more embodiments.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments for the present application include a gas distribution platehaving high aspect ratio holes for a showerhead assembly. The gasdistribution plate includes a plurality of holes through which aprocessing gas may flow. In many instances, by decreasing the size ofeach of the plurality of holes and by increasing the number of theplurality of holes, the uniformity of the process gas which is appliedto a substrate during processing may also be improved. Accordingly,embodiments of the following disclosure describe a gas distributionplate having a high number of small holes and a method for generatingsuch a gas distribution plate while maintaining sufficient thickness ofthe gas distribution plate for adequate strength.

FIG. 1 illustrates a gas distribution plate 100, according to one ormore embodiments. The gas distribution plate 100 includes a plate 110 ₁and a plate 1102. The plate 110 ₁ may be connected to the plate 110 ₂forming the gas distribution plate 100. Further, the gas distributionplate 100 may be part of a showerhead assembly, e.g., the showerheadassembly 616 of FIG. 6 .

The plate 110 ₁ comprises holes 112 ₁. Further, the plate 110 ₁ may beformed of aluminum, an aluminum alloy, molybdenum, a molybdenum alloy,nickel, a nickel alloy, or silicon, among others. The number of holes112 ₁ may be about 50,000 or greater. Further, the number of holes 112 ₁may be about 100,000 or greater. The diameter of each hole 112 ₁ may beat least about 100 um. Further, the diameter of each hole 112 ₁ may beabout 100 um to about 600 um. Alternatively, the diameter of each hole112 ₁ may be less than about 100 um or greater than about 600 um.Further, each hole 112 ₁ may be of a common size (e.g., a commondiameter). Alternatively, the diameter of one or more holes 112 ₁differs from the diameter of another one of the holes 112 ₁.

Each of the holes 112 ₁ may have a uniform diameter. For example, theaspect ratio of each of the holes 112 ₁ may be substantially constantsuch that the diameter at any point within each hole 112 ₁ is the same,or within a manufacturing tolerance, as the diameter at any other pointwithin each hole 112 ₁. Further, the size of each hole 112 ₁ at a firstside of the plate 110 ₁ is the same, or within a manufacturingtolerance, as the size of each hole 112 ₁ at a second side of the plate110 ₁. Alternatively, as will be described in greater detail with regardto the embodiment of FIGS. 4C, the diameter of a hole on a first side ofthe plate 110 ₁ may differ from the diameter of the hole on a secondside of the plate 110 ₁.

The thickness 116 of the plate 110 ₁ may be in a range of about 200 umto about 900 um. Alternatively, the thickness 116 of the plate 110 ₁ maybe less than about 200 um or greater than about 900 um.

The plate 110 ₂ includes holes 112 ₂. The plate 110 ₂ may be formed ofaluminum, an aluminum alloy, molybdenum, a molybdenum alloy, nickel, anickel alloy, or silicon, among others. Further, the plate 110 ₂ may beformed of the same material as plate 110 ₁ or a different material fromplate 110 ₁. The number of holes 112 ₂ may be about 50,000 or greater.Further, the number of holes 112 ₂ may be about 100,000 or greater. Thenumber of holes 112 ₂ may be the same as the number of holes 112 ₁. Thediameter of each hole 112 ₂ may be about 100 um to about 600 um.Alternatively, the diameter of each hole 112 ₂ may be less than about100 um or greater than about 600 um. Further, each hole 112 ₂ may be ofa common size (e.g., a common diameter). Alternatively, the diameter ofone or more holes 112 ₂ differs from the diameter of another one of theholes 112 ₂. Additionally, the diameter of each of the holes 112 ₂ maybe the same as the diameter of each of the holes 112 ₁, or one or moreholes 112 ₂ differs from the diameter of one or more of the holes 112 ₁.

Each of the holes 112 ₂ may have a uniform diameter. For example, theaspect ratio of each of the holes 112 ₂ may be substantially constantsuch that the diameter at any point of within each hole 112 ₂ is thesame, or within a manufacturing tolerance, as the diameter at any otherpoint within each hole 112 ₂. Further, the size of each hole 112 ₂ at afirst side of the plate 110 ₂ is the same, or within a manufacturingtolerance, as the size of each hole 112 ₁ at a second side of the plate110 ₂. Alternatively, as will be described in greater detail with regardto at least the embodiment of FIG. 4C, the diameter of a hole on a firstside of the plate 110 ₁ may differ from the diameter of the hole on asecond side of the plate 110 ₁.

The thickness 126 of the plate 110 ₂ may be in a range of about 200 umto about 900 um. Alternatively, the thickness 126 of the plate 110 ₂ maybe less than about 200 um or greater than about 900 um.

The gas distribution plate 100 and the plates 110 ₁, 110 ₂ may have acircular shape. For example, the gas distribution plate 100 may have acircular shape with a diameter in a range of about 200 mm to about 350mm. Alternatively, the gas distribution plate 100 may have a diameter ofless than about 200 mm or greater than about 350 mm. Further, the gasdistribution plate 100 may have other shapes than a circular shape. Forexample, the gas distribution plate 100 may have an elliptical shape ora rectangular shape, among others. Further, while the gas distributionplate 100 is shown as including 2 plates, e.g., plate 110 ₁ and plate110 ₂, the gas distribution plate 100 may include more than 2 plates.For example, as is illustrated in FIG. 3 , the gas distribution plate100 may include 110 _(N) plates, where N is greater than 2. Further, thetotal thickness of the gas distribution plate 100 may be about 25.4 mm.Alternatively, the total thickness of the gas distribution plate 100 maybe less than about 25.4 mm or greater than about 25.4 mm.

The plates 110 ₁, 110 ₂ may be joined together to form the gasdistribution plate 100. For example, as is illustrated in FIG. 2A, theplates 110 ₁, 110 ₂ may be joined together, forming the gas distributionplate 100 and a plurality of interconnected holes 212.

FIG. 2A illustrates the gas distribution plate 100, according to anembodiment. The gas distribution plate 100 of FIG. 2A includes acombined plate 210 that is formed by joining or coupling the plates 110₁, 110 ₂ together such that each of the holes 112 ₁ is aligned with arespective one of the holes 112 ₂. Aligning each of the holes 112 ₁ withrespective ones the holes 112 ₂ forms a plurality of interconnectedholes 212. Each of the interconnected holes 212 is formed from one ofthe holes 112 ₁ and one of the holes 112 ₂. Further, each of theinterconnected holes 212 may be isolated from each other interconnectedhole. For example, a processing gas may flow through each of theinterconnected holes 212 but not between the interconnected holes 212.Further, each of the interconnected holes 212 may be same shape and/orsize.

The combined plate 210 may be formed from a number of plates greaterthan 2. For example, the combined plate 210 may be formed from of atleast N plates, where N is 3 or more. The combined plate 210 may beformed from at least 10 plates. Further, the combined plate 210 may beformed from at least 100 plates.

FIG. 2B illustrates a portion of a combined plate 210, according to oneor more embodiments. The interconnected hole 212 a has a diameter 214and a height 216. Further, an aspect ratio of the interconnected hole212 may be based on a ratio of the height 216 to the diameter 214. Forexample, the interconnected hole 212 a may have an aspect ratio of atleast about 50 to 1. Alternatively, the interconnected hole 212 a mayhave an aspect ratio of less than about 50 to 1 or greater than about 50to 1. Further, the interconnected hole 212 a may have an aspect ratio ofabout 25 to 1. Additionally, each of interconnected holes 212 may haveabout the same aspect ratio.

The diameter of each of the interconnected holes 212 may besubstantially uniform. For example, at any point of an interconnectedhole the diameter is the same, or within a manufacturing tolerance, ofany other point of the interconnected hole. Stated another way, theaspect ratio of each interconnected holes is uniform or substantiallysimilar (e.g., within a manufacturing tolerance) throughout the entiretyof each interconnected hole. Further, the diameter of eachinterconnected hole 212 at a first side (e.g., surface) of the combinedplate 210 is the same as the diameter of each interconnected hole 212 ata second side (e.g., surface) of the combined plate 210.

FIG. 3 illustrates the gas distribution plate 100, according to one ormore embodiments. The gas distribution plate 100 of FIG. 3 includes thecombined plate 300 formed by joining the plate 110 ₁, the plate 110 ₂,and a plate 110 _(N), where N is greater than 2. Further, the holes 112₁ of the plate 110 ₁, the holes 112 ₂ of the plate 110 ₂, and the holes112 _(N) of the plate 110 _(N) are aligned to generate a plurality ofinterconnected holes.

FIG. 4A illustrates plates 410 ₁ and 410 ₂ of a gas distribution plate400 a, according to one or more embodiments. While two plates areillustrated in the embodiment of FIG. 4A, alternatively, the gasdistribution plate 400 b may include three or more plates. Further, theplate 410 ₁ may be bonded to the plate 410 ₂ forming the gasdistribution plate 400 a. Additionally, the gas distribution plate 400 amay be part of a showerhead assembly, e.g., the showerhead assembly 616of FIG. 6 .

The plate 410 ₁ includes holes 412 ₁ and may be formed similar to thatof plate 110 ₁ and 110 ₂. Further, the plate 410 ₂ includes holes 412 ₂and may be formed similar to that of plate 110 ₁ and 110 ₂.

The diameter of each of the holes 412 ₂ may differ from the diameterfrom the diameter of each of the holes 412 ₁. For example, the diameterof the holes 412 ₁ along surface 424 of the plate 410 ₁ is larger thanthe diameter of the holes 412 ₂ along the surface 426 of the plate 410₂. Further, the diameter of the holes 412 ₂ along the surface 426 may bethe same or may differ from the diameter of the holes 412 ₂ along thesurface 428. For example, the diameter of the holes 412 ₂ along thesurface 426 may be larger or smaller than the diameter of the holes 412₂ along the surface 428.

Utilizing plates having holes with different diameters may aid in thealignment of the plates before bonding to the plates together. Forexample, utilizing holes of different diameter allow for slight offsetsin alignment of the holes while maintaining a similar cross section areafor the gas flow as compared to utilizing holes of a common diameterwhich are fully aligned with each other.

FIG. 4B illustrates a portion of gas distribution plate 400 a, accordingto one or more embodiments. In particular, FIG. 4B illustrates aninterconnected hole 440 a of gas distribution plate 400 a formed afterbonding the plate 410 ₁ with the plate 410 ₂. For example, theinterconnected hole 440 a is formed by joining the plate 410 ₁ with theplate 410 ₂, and comprises one of holes 412 ₁ and one of holes 412 ₂.Further, the diameter of interconnected hole 440 is non-uniform (i.e., anon-uniform diameter). For example, the diameter of the interconnectedhole 440 a along the surface 422 differs from the diameter of theinterconnected hole 440 along the side 428. As illustrated in FIG. 4B,the diameter of the interconnected hole 440 a along the surface 422 islarger than the diameter of the interconnected hole 440 a along thesurface 428. Alternatively, the diameter of the interconnected hole 440a along the surface 422 may be smaller than the diameter of theinterconnected hole 440 a along the surface 428.

FIG. 4C illustrates plates 410 ₃ and 410 ₄ of a gas distribution plate400 b, according to one or more embodiments. While two plates areillustrated in the embodiment of FIG. 4C, alternatively, the gasdistribution plate 400 b may include three or more plates. Further, theplate 410 ₃ may be bonded to the plate 410 ₄ forming the gasdistribution plate 400 b. Additionally, the gas distribution plate 400 bmay be part of a showerhead assembly, e.g., the showerhead assembly 616of FIG. 6 .

The plate 410 ₃ includes holes 412 ₃ and may be formed similar to thatof plate 110 ₁ and 110 ₂. The plate 410 ₄ includes holes 412 ₄ and maybe formed similar to that of plate 110 ₁ and 110 ₂.

Similar to that of plates 410 ₁ and 410 ₂, the diameter of each of theholes 412 ₃ may differ from the diameter from the diameter of each ofthe holes 412 ₄. However, the holes 412 ₃ and/or the holes 412 ₄ mayinclude a tapered region. For example, the holes 412 ₄ include a taperedregion 434. Accordingly, the diameter of the holes 412 ₄ is non-uniform.For example, the diameter of the holes 412 ₄ along the surface 426 islarger than the diameter of the holes 412 ₄ along surface 428.Additionally, or alternatively, the diameter of the holes 412 ₃ may benon-uniform. For example, the diameter of the holes 412 ₃ along one ofthe surfaces 422 and 424 may differ from the diameter of the holes 412 ₃along the other one of the surfaces 422 and 424. Further, the holes 412₃ may include a tapered region.

FIG. 4D illustrates a portion of gas distribution plate 400 b, accordingto one or more embodiments. In particular, FIG. 4D illustrates aninterconnected hole 440 b of gas distribution plate 400 b formed afterbonding the plate 410 ₃ with the plate 410 ₄. For example, theinterconnected hole 440 a is formed by joining the plate 410 ₃ with theplate 410 ₄, and comprises one of holes 412 ₃ and one of holes 412 ₄.Accordingly, the diameter of interconnected hole 440 b is non-uniform,differing between surface 422 and surface 428, and the interconnectedhole 440 b includes a tapered region 434. The diameter of theinterconnected hole 440 b along surface 422 may be larger or smallerthan the diameter of the interconnected hole 440 b along surface 428.

FIG. 4E illustrates an interconnected hole 440 c, according to one ormore embodiments. The interconnected hole 440 c may be formed from holesin two or more plates as illustrated in the embodiments of FIGS. 1, 3,4A and/or 4C and described in the corresponding description. Asillustrated in FIG. 4E, the interconnected hole 440 c includes a taperedregion 444 disposed along the surface 422. Further, the diameter of theinterconnected hole 440 c is non-uniform, varying between the surface422 and 428.

FIG. 4F illustrates an interconnected hole 440 d, according to one ormore embodiments. The interconnected hole 440 d may be formed from holesin two or more plates as illustrated in the embodiments of FIGS. 1, 3,4A and/or 4C and described in the corresponding description. Asillustrated in FIG. 4F, the interconnected hole 440 d includes a taperedregion 454 disposed along the surface 422 and tapered region 456disposed between the surface 422 and 428. Further, the diameter of theinterconnected hole 440 d is non-uniform, varying between the surface422 and 428.

FIG. 4G illustrates an interconnected hole 440 e, according to one ormore embodiments. The interconnected hole 440 e may be formed from holesin two or more plates as illustrated in the embodiments of FIGS. 1, 3,4A and/or 4C and described in the corresponding description. Asillustrated in FIG. 4G, the interconnected hole 440 e includes a taperedregions 464 disposed along the surface 422 and tapered region 466disposed along the surface 428. Further, the diameter of theinterconnected hole 440 e is non-uniform, varying between the surface422 and 428. The diameter of the interconnected hole 440 e along thesurface 422 may be similar to (e.g., within a manufacturing tolerance)the diameter of the interconnected hole 440 e along surface 428.Alternatively, the diameter of the interconnected hole 440 e along thesurface 422 differs from the diameter of the interconnected hole 440 ealong surface 428. For example, the diameter of the interconnected hole440 e along the surface 422 is greater than or less than the diameter ofthe interconnected hole 440 e along surface 428.

FIG. 4H illustrates an interconnected hole 440 f, according to one ormore embodiments. The interconnected hole 440 f may be formed from holesin two or more plates as illustrated in the embodiments of FIGS. 1, 3,4A and/or 4C and described in the corresponding description. Asillustrated in FIG. 4H, the interconnected hole 440 f includes a taperedregion 474 disposed along the surface 428. Further, the diameter of theinterconnected hole 440 f is non-uniform, varying between the surface422 and 428.

FIG. 4I illustrates an interconnected hole 440 e, according to one ormore embodiments. The interconnected hole 440 g may be formed from holesin two or more plates as illustrated in the embodiments of FIGS. 1, 3,4A and/or 4C and described in the corresponding description. Asillustrated in FIG. 4I, the interconnected hole 440 g includes a taperedregion 484 disposed along the surface 422 and tapered region 486disposed along the surface 428. Further, the diameter of theinterconnected hole 440 g is non-uniform, varying between the surface422 and 428. In one or more embodiments, the diameter of theinterconnected hole 440 g along the surface 422 is greater than thediameter of the interconnected hole 440 g along surface 428.Alternatively, the diameter of the interconnected hole 440 g along thesurface 428 may be greater than the diameter of the interconnected hole440 g along surface 422.

The plates 110 ₁, 110 ₂, 110 _(N) may be bonded using any methodsuitable for bonding the plates without damaging the plates and whilemaintaining an independence between the interconnected holes. Forexample, FIG. 5 illustrates a flowchart of a method for bonding platesto generate a gas distribution plate 100, according to one or moreembodiments. At operation 510, a plurality of holes is generated in afirst plate. For example, as is shown in FIG. 1 , the holes 112 ₁ aregenerated in plate 110 ₁. The holes 112 ₁ may be generated through aprocess of mechanical drilling, ultrasonic drilling, laser drilling,electro-discharge machining, or any other subtractive fabricationmethod.

At operation 520, a plurality of holes is generated in a second plate.For example, as is shown in FIG. 1 , the holes 112 ₂ are generated inthe plate 110 ₂. The holes 112 ₁ may be generated through a process ofmechanical drilling, ultrasonic drilling, laser drilling,electro-discharge machining, or any other subtractive fabricationmethod. Further, a similar method may be used to generate holes in anynumber of plates.

At operation 530, the plates are prepared for bonding. For example, thesurfaces of plates 110 and 410 may be prepared for bonding to ensurethat the surfaces are flat and clean to facilitate proper bonding of theplates. Preparing the surfaces for bonding may include one or more ofpolishing the surfaces, lapping the surfaces, cleaning the surfaces, andetching the surfaces, among others.

At operation 540, each of the plurality holes of the first plate isaligned with a respective one of the plurality of holes of the secondplate. For example each of the holes 112 ₁ may be aligned with arespective one of the holes 112 ₂ forming a plurality of interconnectedholes 212. Further, in embodiments where more than two plates areutilized to form a combined plate, the holes from any two plates may bealigned to form a plurality interconnected holes. Each of theinterconnected holes may be formed from a hole from each of the platesutilized to form the gas distribution plate 100.

At operation 550, the first plate is bonded with the second plate. Forexample, the plates may be together using a brazing method (i.e.,brazing technique), or a diffusion bonding method (i.e., a diffusionbonding technique), among others.

In a brazing method, the holes are aligned, the plates are stacked and abraze, or filler, sheet may be disposed and sandwiched between theplates. For example, the plate 110 ₁ may be stacked with plate 110 ₂ andeach of the holes 112 ₁ may be aligned with a respective one of theholes 112 ₂. Additionally, after the braze sheets are placed on a plateand before the plates are stacked, the portions of the braze sheets thatmay be overlapping a hole in the corresponding plate may be removed.After alignment of the plates 110 ₁ and 110 ₂, the brazing process maybe completed. For example, temperature at or above the meltingtemperature of the braze sheets may be applied to the gas distributionplate 100, to melt the braze sheets and join the plate 110 ₁ with theplate 110 ₂.

In a diffusion bonding method, each plate of the gas distribution plate100 may be stacked and the holes of each plate may be aligned. Forexample, the plate 110 ₁ may be stacked with plate 110 ₂ and each of theholes 112 ₁ may be aligned with a respective one of the holes 112 ₂.After stacking the plates and aligning the holes, the diffusing bondingprocess may be completed. Further, aligning the holes may includeorienting the plates such that the rolling directions of the rawmaterial of each of the plates are aligned. Orienting the rollingdirections of the plates may ensure that any mismatches in materialproperties based on the direction of the raw material for plates doesnot impact the bonding and performance of the gas distribution plate.The rolling direction may be parallel to the structural lines on thesurface of the plates created during as a result of the manufactureprocess utilized to crate the plates.

At operation 560, the gas distribution plate formed by bonding the firstand second plates is cleaned. For example, in one embodiment, after thecompletion of the boding process, the gas distribution plate may becleaned using any suitable chemical cleaning process. At operation 570,the gas distribution plate 100, 400 may be coated with an oxide, forminga coating on the gas distribution plate, using an atomic layerdeposition (ALD) method, or any other process that is able to deposit alayer on the gas distribution plate 100, 400 such that a processing gasmay still pass through the interconnected holes. For example, the gasdistribution plate 100, 400 may be coated within an oxide, such asAluminum oxide or Yttrium oxide, among others.

FIG. 6 illustrates a schematic sectional view of a processing chamber600 according to one embodiment. The processing chamber 600 may be usedto process one or more substrates 640 therein, including the processesof depositing a material on the substrate 640, heating of the substrate640, etching of the substrate 640, or combinations thereof. Theprocessing chamber 600 may be an atomic layer deposition (ALD) chamber.Further, the processing chamber 600 may be a chemical vapor deposition(CVD) processing chamber, a plasma-enhanced chemical vapor deposition(PECVD) processing chamber, or a physical vapor deposition (PVD)processing chamber, among others.

In one or more embodiments, the processing chamber 600 has an internalregion 611 that includes a substrate support 642 disposed therein tosupport a substrate 640. The substrate support 642 includes a heatingelement 618 and an element that retains the substrate 640 on a topsurface of the substrate support 642, such as an electrostatic chuck, avacuum chuck, a substrate retaining clamp, or the like. The substratesupport 642 may be coupled to and movably disposed in the internalregion 611 by a stem 610 connected to a lift system that moves thesubstrate support 642 between an elevated processing position and alowered position that facilitates transfer of the substrate 640 to andfrom the processing chamber 600 through an opening 624.

The processing chamber 600 may include a gas supply source 626. In oneor more embodiment, the gas supply source 626 may include a mass flowcontrol (MFC) device, disposed between a gas source and the internalregion 611 to control a flow rate of process gas or gasses from the gassource to the gas distribution plate 100 of a showerhead assembly 616used for distributing the process gasses across the internal region 611.For example, the process gas may flow through gas inlet 614 and throughthe holes of the gas distribution plate 100. The showerhead assembly 616is coupled to the processing chamber 600. For example, the showerheadassembly 616 may be coupled to the processing chamber 600 to positionthe gas distribution plate 100 above the substrate 640. The gasdistribution plate 100 may be centered over the substrate 640. Further,the gas distribution plate 100 may be larger than the substrate 640 suchthat the edges of the gas distribution plate 100 extend beyond the edgesof the substrate 640. The showerhead assembly 616 may be connected to aRF power source for generating a plasma in the internal region 611 froma process gasses. Moreover, a deposition process may be utilized toprocess the substrate 640 at a processing pressure to deposit or grow afilm onto the substrate 640.

The stem 610 is configured to move the substrate support 642 to anelevated processing position to process the substrate 640. Further, avacuum pump 657 may be coupled to the internal region 611 and controlthe pressure within the internal region 611.

A process gas, such as a deposition gas or cleaning chemistry, may besupplied from a gas supply source 627 into the internal region 611through the gas inlet 613 of the processing chamber 600. Further, theprocess gas may exit the process gas region through the gas outlet 636.Removal of the process gas, including cleaning chemistry, through thegas outlet 636 is facilitated by a vacuum pump 657 coupled to the gasoutlet 636.

The above-described processing chamber 600 can be controlled by aprocessor based system controller, such as controller 630. For example,the controller 630 is configured to control flow of various precursorgases, process gases, and purge gases, during different operations of asubstrate processing sequence. By way of further example, the controller630 is configured to control feeding of gases, lamp operation, or otherprocess parameters, among other controller operations.

The controller 630 is generally used to facilitate the control andautomation of the components within the processing chamber 600. Thecontroller 630 can be, for example, a computer, a programmable logiccontroller, or an embedded controller. The controller 630 typicallyincludes a central processing unit (CPU) 632 memory 634, and supportcircuits for inputs and outputs (I/O). The CPU 632 may be one of anyform of computer processors that are used in industrial settings forcontrolling various system functions, substrate movement, chamberprocesses, and control support hardware (e.g., sensors, motors, heaters,etc.), and monitor the processes performed in the processing chamber600. The memory 634 is connected to the CPU 632, and may be one or moreof a readily available non-volatile memory, such as random access memory(RAM), flash memory, read only memory (ROM), floppy disk, hard disk, orany other form of digital storage, local or remote. Softwareinstructions and data can be coded and stored within the memory forinstructing the CPU 632. The support circuits are also connected to theCPU 632 for supporting the processor in a conventional manner. Thesupport circuits may include cache, power supplies, clock circuits,input/output circuitry, subsystems, and the like. A program (e.g.,software routine or computer instructions) readable by the controller630 determines which tasks are performable by the components in theprocessing chamber 600. Preferably, the program is software readable bythe processor within the controller 630 that includes code to performtasks relating to monitoring, execution and control of the delivery andcontrol of the process variables utilized in one or more the processesperformed within the processing chamber 600, and the movement, support,and/or positioning of the substrate 640 and other components within theprocessing chamber 600 along with the various process tasks and varioussequences being controlled the by controller 630.

A gas distribution plate may be formed to increase in the uniformity ofthe process gas applied to a substrate during processing of thesubstrate. The gas distribution plate may be formed by joining two ormore plates together. Each of the plates may have a plurality of holesformed therein, and each of the holes in a first one of the plates isaligned with a respective hole in a second one of the plates. When theplates are joined, the aligned holes form a plurality of interconnectedholes. Further, by forming the holes in thinner plates which are joinedto generate the gas distribution plate, the holes may have a higheraspect ratio than if the holes were formed in a thicker gas distributionplate formed from a single plate. Further, the number of holes that maybe formed in each plate may be greater than the total number of holesthat may be formed in a gas distribution plate formed from a singleplate.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1-20. (cancelled)
 21. A gas distribution plate for a showerheadassembly, the gas distribution plate comprising: a first platecomprising a plurality of first holes, each first hole having a diameterof at least 100 um; and a second plate coupled to the first plate, thesecond plate comprising a plurality of second holes, each second holehaving a diameter of at least 100 um and aligned with a respective firsthole of the plurality of first holes to form a plurality ofinterconnected holes, each interconnected hole isolated from each otherinterconnected hole of the plurality of interconnected holes; wherein:the coupled first and second plates form a structure including a topsurface and a bottom surface; and each interconnected hole comprises: afirst diameter at the top surface; a transition from the first diameterto a smaller second diameter below the top surface, the transitionincluding a step change in hole diameter; and a frustoconical taper fromthe second diameter to a larger third diameter at the bottom surface.22. The gas distribution plate of claim 21, wherein the step change inhole diameter corresponds to an interface of a lower surface of thefirst plate and an upper surface of the second plate.
 23. The gasdistribution plate of claim 21, wherein each interconnected hole furthercomprises a first portion of uniform diameter equal to the firstdiameter and extending from the top surface to the transition.
 24. Thegas distribution plate of claim 23, wherein each interconnected holefurther comprises a second portion of uniform diameter equal to thesecond diameter and extending from the transition to the frustoconicaltaper.
 25. The gas distribution plate of claim 24, further comprising anoxide coating applied to the coupled first and second plates.
 26. Thegas distribution plate of claim 21, wherein each of the plurality ofinterconnected holes has an aspect ratio of at least 25 to
 1. 27. Thegas distribution plate of claim 21, wherein each of the plurality offirst holes and each of the plurality of second holes has a diameter of100 um to about 600 um.
 28. The gas distribution plate of claim 21,wherein each of the first plate and the second plate has a thickness ina range of about 100 um to about 12.7 mm.
 29. The gas distribution plateof claim 21, wherein: the gas distribution plate further comprises athird plate coupled to the second plate; the third plate comprises aplurality of third holes; and each third hole of the plurality of thirdholes is aligned with a respective first hole of the plurality of firstholes and a respective second hole of the plurality of second holes. 30.The gas distribution plate of claim 21, wherein the first plate isbonded to the second plate using one of a diffusion bonding technique ora brazing technique.
 31. A gas distribution plate, comprising: a firstplate comprising a plurality of first holes, each first hole having adiameter of at least 100 um; and a second plate coupled to the firstplate, the second plate comprising a plurality of second holes, eachsecond hole having a diameter of at least 100 um and aligned with arespective first hole of the plurality of first holes to form aplurality of interconnected holes, each interconnected hole isolatedfrom each other interconnected hole of the plurality of interconnectedholes; wherein: exposed surfaces of the coupled first and second platecomprise an oxide coating; the coupled first and second plates form astructure including a top surface and a bottom surface; and eachinterconnected hole comprises: a first diameter at the top surface; atransition from the first diameter to a smaller second diameter belowthe top surface, the transition including a step change in holediameter; and a frustoconical taper from the second diameter to a largerthird diameter at the bottom surface.
 32. The gas distribution plate ofclaim 31, wherein the step change in hole diameter corresponds to aninterface of a lower surface of the first plate and an upper surface ofthe second plate.
 33. The gas distribution plate of claim 31, whereineach interconnected hole further comprises a first portion of uniformdiameter equal to the first diameter and extending from the top surfaceto the transition.
 34. The gas distribution plate of claim 33, whereineach interconnected hole further comprises a second portion of uniformdiameter equal to the second diameter and extending from the transitionto the frustoconical taper.
 35. The gas distribution plate of claim 31,wherein the oxide coating comprises yttrium oxide.
 36. The gasdistribution plate of claim 31, wherein each of the plurality ofinterconnected holes has an aspect ratio of at least 25 to
 1. 37. Thegas distribution plate of claim 31, wherein each of the plurality offirst holes and each of the plurality of second holes has a diameter of100 um to about 600 um.
 38. The gas distribution plate of claim 31,wherein each of the first plate and the second plate has a thickness ina range of about 100 um to about 12.7 mm.
 39. The gas distribution plateof claim 31, wherein: the gas distribution plate further comprises athird plate coupled to the second plate; the third plate comprises aplurality of third holes; and each third hole of the plurality of thirdholes is aligned with a respective first hole of the plurality of firstholes and a respective second hole of the plurality of second holes. 40.A gas distribution plate, comprising: a first plate comprising aplurality of first holes, each first hole having a diameter of at least100 um, the first plate having a thickness within a range of 100 um toabout 12.7 mm; and a second plate coupled to the first plate, the secondplate having a thickness within a range of 100 um to about 12.7 mm, thesecond plate comprising a plurality of second holes, each second holehaving a diameter of at least 100 um and aligned with a respective firsthole of the plurality of first holes to form a plurality ofinterconnected holes, each interconnected hole isolated from each otherinterconnected hole of the plurality of interconnected holes; wherein:exposed surfaces of the coupled first and second plate comprise anyttrium oxide or aluminum oxide coating; the coupled first and secondplates form a structure including a top surface and a bottom surface;and each interconnected hole comprises: a first diameter at the topsurface; a transition from the first diameter to a smaller seconddiameter below the top surface, the transition including a step changein hole diameter; and a frustoconical taper from the second diameter toa larger third diameter at the bottom surface.